1. Field of the Invention
The present invention relates to a noncontact gage system for determining spatial characteristics of an object such as size, shape and/or relative location of selected portions of the object by directing incident light onto selected surface portions of an object to form an illuminated area thereon, and by focusing reflected light from the illuminated area along a path that is intercepted by a light sensitive detector. The detector provides an output signal that is representative of a characteristic of the selected surface portion of the object, typically its location. By determining relative locations of various features of the object, its size and shape may be deduced. The signal from the detector is preferably electronically processed, and values of the processed signal are compared with predetermined values, sampled and/or stored. Stated in another way, the present invention relates to a noncontact sensing and measuring system that utilizes incident and reflected light to interrogate an object, with the system being suitable for making dimensional and geometrical measurements on a wide variety of surfaces and objects. A microcomputer may be used to monitor and control gage operation, to collect and compare data to predetermined desired values, and/or to determine and control needed machining.
2. Prior Art
Industrial metrology is concerned with measuring dimensions, geometry, and surface finish characteristics of manufactured parts. As the study of this science and art has progressed, many types of measuring devices and techniques have evolved to answer recurring questions about desired degrees of conformance of spatial characteristics of objects, for example whether dimensions are within tolerance, total runout is within acceptable limits, surface smoothness is within predetermined specifications, related surfaces are flat and parallel or round and concentric, selected surface portions are properly located relative to each other, and the like.
Despite a continuum of development, a need persists for improved methods and means that will enable selected spatial characteristics of an object to be quickly, easily, and yet accurately ascertained and compared with desired values. A need also remains for an integrated system that has a capability not only to sense, store and compare data about spatial characteristics of objects, but also to determine and control the character of additional machining that is needed to bring spatial features of an object into conformance with desired limits.